Axially arranged rotary threshing or separating systems have long been in use in agricultural combines for threshing crops to separate grain from crop residue, also referred to as material other than grain (MOG). Such axially arranged systems typically include at least one cylindrical rotor rotated within a concave or cage, the rotor and surrounding concave being oriented so as to extend forwardly to rearwardly within the combine.
In operation, crop material is fed or directed into a circumferential passage between the rotor and concave and is carried rearwardly therebetween by the rotation of the rotor along a generally helical path as grain is threshed from the crop material. The flow of crop residue or MOG remaining between the rotor and concave after threshing is typically discharged or expelled by the rotating rotor from a discharge opening at a rear end of the passage in a generally downward, or a downward and sidewardly direction in what is a continuation of the helical path of movement of the crop residue within the passage between the rotor and concave.
The flow is typically discharged into a passage which extends downwardly and somewhat rearwardly into a crop residue distribution system located below and rearwardly of the rear end of the threshing system, and which typically includes a rotary beater or other apparatus which propels the crop residue rearwardly within a rear end of the combine for either discharge from the combine through a rear opening onto a field, or into a chopper and/or spreader mounted on the rear end operable for spreading the residue over a swath of a field.
When spread in a swath over a field, it is desirable in many instances for the crop residue to be distributed evenly or uniformly over the swath. This is desirable for reasons including that uneven crop residue distribution on a field can lead to temperature and moisture gradients detrimental to even growth of future crops on the field. It can also make it difficult for crops to utilize nutrients, and can impact the effectiveness of agricultural chemicals. Large discontinuities of crop residue can lead to plugging and other functional problems with tillage and/or planting equipment.
One factor which has been found to influence the ability of a chopper and/or spreader to distribute crop residue evenly or uniformly over a field is the transverse or side to side evenness of crop residue inflow into the chopper and/or spreader. That is, it has been found that the amount of crop residue infeed to one side of the chopper should be about equal to infeed to the over side to achieve even distribution over a field. In turn, the side to side infeed to the chopper/spreader has been found to be a function of the side to side distribution of crop residue infeed into the beater or other impeller of the crop residue distribution system from the threshing system.
Numerous devices and structures have been developed to improve flow of crop residue from axially arranged threshing systems into crop residue distribution systems. Reference in this regard, Payne et al., U.S. Pat. No. 6,352,474 entitled Metering Edge for Axially Arranged Rotary Separator, and Pfeiffer et al., U.S. Pat. No. 6,241,605 entitled Discharge Geometry for Axially Arranged Rotary Separator.
Although the above referenced apparatus may perform well, it has been found that a variety of variables and conditions can influence the ability to redirect and transversely distribute crop residue flow in the passage between a threshing system and a crop residue distribution system.
For instance, residue from different crops, such as wheat and corn, will typically flow differently, and different rotor rotation speeds will typically be used for different crops. For instance, small grains such as wheat and other grasses will typically be threshed at a relatively high rotor speed, for instance, 600 to 1000 revolutions per minute (rpm), and produce residue containing a large volume of small stalks of straw, and, whereas corn will typically be threshed at a relatively slow rotor speed, for instance, less than 400 rpm, and produce crop residue containing a mixture of bulky stalk segments, cob fragments and large leaves. For a given crop, differences in plant maturity and weather conditions can affect size, moisture content, and other characteristics of crop residue so as to have varying flow and distribution characteristics.
As a result of the above described variables and conditions, it has been observed that the transition of crop residue flow from the threshing system to the residue distribution system can vary. In particular, the side to side distribution of the flow into the rotating beater can vary, that is, flow to one side of the beater can be heavier than to the other side, such that the beater will propel more crop residue into one side of a chopper and/or spreader, resulting, in turn, in uneven crop residue distribution over a swath of a field.
Thus, what is sought is an apparatus for transitioning crop residue from an axially arranged threshing system of a combine to a distribution system, that overcomes one or more of the problems and disadvantages set forth above.